Device Having a Casing and/or Interior Acting as a Communication Bus Between Electronic Components

ABSTRACT

A device other than a projectile including: a casing, at least a portion of which contains a potting material acting as the optical waveguide material; a transmitter for transmitting a pulse based signal at least partially through the potting material; and a receiver for receiving the pulse based signal after one or more reflections of the pulse based signal from interior surfaces of the casing; the pulse based signal having a pulse rate configured such that a subsequent pulse doesn&#39;t interfere with reflections from an immediately previous pulse.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation-in-part of U.S. application Ser. No.11/899,731 filed on Sep. 7, 2007 which is a divisional application ofU.S. application Ser. No. 10/639,001 filed on Aug. 12, 2003, now U.S.Pat. No. 7,272,293, the entire contents of which is incorporated hereinby reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates generally to devices, and moreparticularly, to devices having a casing and/or interior that act as acommunication bus between at least two components of the device. Forpurposes of this disclosure, a device is any article having a casingwhich houses two or more electrical/electronic components. Also forpurposes of this disclosure, a communication bus is anything thattransmits one or more signals between two or more components. Suchtransmission may be one-way or two-way. Thus, the transmission may be asimple point-to-point link between two components or a point to manylinks between several components. Furthermore, the transmission may besuch that the transmitted signal(s) are available to any components onthe communication bus. Still further, the communication bus may be morethan one media, such as a waveguide, potting material, and/or free spacein the casing (including the casing itself).

2. Prior Art

Electronic devices typically have a casing or shell in whichelectronic/electrical components are housed. The electronic/electrical(collectively referred to hereinafter as “electronic” or “electronics”)components interact with each other and/or other devices via internalwiring (which includes printed circuit boards). While the wiring has itsadvantages, it suffers from certain disadvantages such as susceptibilityto noise, brittleness, potential for high bit error, takes up a largeamount of space in the interior of the casing or shell, can suffer frompoor connections, and may be susceptible to impact and shock. Thesedisadvantages are amplified in certain devices that house electroniccomponents and operate in harsh environments.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide methods and devicesthat overcome the disadvantages of the wiring used to link components indevices having electronic components.

Accordingly, a device other than a projectile is provided. The devicecomprising: a casing, at least a portion of which contains a pottingmaterial acting as the optical waveguide material; a transmitter fortransmitting a pulse based signal at least partially through the pottingmaterial; and a receiver for receiving the pulse based signal after oneor more reflections of the pulse based signal from interior surfaces ofthe casing; the pulse based signal having a pulse rate configured suchthat a subsequent pulse doesn't interfere with reflections from animmediately previous pulse.

The potting material can be selected from a group consisting of a solid,a gel, and a liquid. Where the potting material is the solid, the solidcan be an epoxy resin.

The signal can be an infrared signal.

The casing can include a window through which an input signal istransmitted from an exterior of the casing to at least one of thepotting material and receiver.

Also provided is a method for transmitting signals between components ina device other than a projectile. The method comprising: filling atleast a portion of the device with a potting material acting as anoptical waveguide material; transmitting a pulse based signal at leastpartially through the potting material acting as the optical waveguidematerial; reflecting the pulse based signal from interior surfaces ofthe device; and receiving the pulse based signal after one or morereflections; wherein the pulse based signal has a pulse rate configuredsuch that a subsequent pulse doesn't interfere with reflections from animmediately previous pulse.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other features, aspects, and advantages of the apparatus andmethods of the present invention will become better understood withregard to the following description, appended claims, and accompanyingdrawings where:

FIG. 1 illustrates a schematic view of a generic electronic devicehaving a casing nose and two or more electronic components according toa first embodiment.

FIGS. 2A, 2B, and 2C illustrate sectional views of a wall of the casingof FIG. 1 as taken along line 2-2 in FIG. 2, FIGS. 2A, 2B, and 2Crepresenting three alternative wall/waveguide configurations.

FIG. 3 illustrates a sectional view of a computer CPU casing accordingto an embodiment.

FIG. 4 illustrates a partial sectional view of a cellular telephoneaccording to an embodiment.

FIG. 5 illustrates a partial sectional view of a cellular telephoneaccording to another embodiment of the present invention.

FIG. 6 illustrates a schematic electrical diagram of an infrared (IR)transceiver for use with the cellular telephone of FIG. 5.

FIG. 7 illustrates a cellular telephone according to another embodimentof the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Although the invention is particularly suited to optical signalcommunication between electronic components, such is discussed by way ofexample only. Those skilled in the art will appreciate that othercommunication means can also be utilized, such as ultrasound. Further,although a generic casing, computer casing, and cellular phone casingare illustrated and discussed herein, such are given by way of exampleonly, those skilled in the art will appreciate that the devices andmethods of the present invention can be utilized in any device having aninterior which houses at least two interconnected electronic components.

Referring now to FIG. 1, there is shown a generic device generallyreferred to by reference numeral 100. The generic device 100 has acasing 102 that defines an interior 104. The casing 102 preferably has ametal, plastic, or composite outer portion 106 and a communication bus,such as waveguide portion 108. The casing 102 is shown generically asrectangular in shape, however, those skilled in the art will appreciatethat it may have any shape. Furthermore, the casing 102 is shown havinga two-piece construction, upper shell 106 a and lower platform 106 bjoined together with screws 107. However, those skilled in the art willappreciate that the casing 102 can be constructed from one or morepieces, and if more than one piece, the pieces can be joined or fastenedin any manner known in the art, such as by welding, gluing, riveting, orwith interference or snaps.

The waveguide portion 108 is preferably optical glass having appropriatecladding as is known in the art. However, the waveguide portion 108 canalso be a synthetic material, such as an acrylic, polycarbonate, orepoxy. The inner waveguide material can be formed on the casing 102 byany methods known in the art, such as by casting, machining, ordepositing. The waveguide portion 108 can be disposed on the entireinner surface of the outer portion 106 of the casing 102 (or a portionthereof) as shown in FIG. 2A. Alternatively, the waveguide portion 108can be arranged in strips 117, formed on the outer portion 106 of thecasing 102 as is shown in FIG. 2C, or in channels 111 formed in theouter portion 106 of the casing 102 as is shown in FIG. 2B.Alternatively, the waveguide portion 108 can make up the entire shell102 (no outer portion 106 is used), which can be uncoated or have acoating, such as an opaque paint.

At least one transmitter 110 is arranged on the waveguide portion 108 orproximate thereto such that a signal 101, such as an optical signal canbe transmitted to the waveguide portion 108. The transmitter 110 can beintegral with a corresponding electronic component 112 or connectedthereto. At another location on the waveguide portion 108 are locateddetectors 114 for detecting the optical signals in the waveguide portion108. Each detector 114 is either integral with or connected to anotherelectronic/electrical component 116. Thus, those skilled in the art willappreciate that any component can communicate with another componentthrough the waveguide portion 108, which acts as a communication bus. Ofcourse, each of the components can have both a transmitter 110 anddetector 114 such that a two-way communication can be achieved.Furthermore, each of the transmitter and detector can itself beconsidered a component operatively connected to the waveguide portion108 (communication bus). Although not shown, mutiplexers anddemultiplexers can be used such that certain components can operate atselected frequencies and/or wavelengths and not interfere with othercomponents on the bus. Similarly, other components known in the art fortransmission of signals through a waveguide can be used, such as anamplifier (not shown) for amplifying a signal between components. Thetransmitters 110 and detectors 114 can be mounted to the waveguideportion 108 directly as is known in the art such as by an opticalquality adhesive, as shown in FIGS. 2A and 2C. Alternatively, thetransmitter 110 and detectors 114 can be mounted to the waveguideportion 108 or the outer portion 106 of the casing 102 by mechanicalmeans, such as a bracket 113 and screws 115 as is shown in FIG. 2B.Also, the transmitters and detectors can be both adhered andmechanically fastened to the waveguide portion 108. As anotheralternative, the components can be connected to the waveguide portion108 by optical fibers (not shown) or the like.

Those skilled in the art will appreciate that the interior 104 is notcluttered with components and internal wiring resulting in morecomponents being able to occupy a given interior size or the device 100being made smaller than a conventional device having the same number ofinternal components. In the device shown in FIG. 1, portion 104 a of theinterior 104 can be used to house additional components or the devicecan be reduced in size to eliminate portion 104 a or a portion thereof.Other advantages include:

The optical transmission provides robust, interference free channelsbetween physically disconnected components/systems;

The optical transmission is naturally resistant to very high g-loads andharsh environments;

For shorter distances between the transmitter and receiver, the systemis inexpensive and extremely low bit rate error (better than 10⁻¹²) canbe readily achieved; and

The need for wires and related problems and space requirements areeliminated.

Alternatively, ultrasound can be used to communicate between theinternal components 112, 116. In which case, the casing 102 or a portionthereof needs to be able to carry an ultrasound signal betweencomponents. Such a casing 102, or portion thereof, may be constructedfrom a suitable metal. In the case of ultrasound, an ultrasonicgenerator is used to place signals on the “bus” (casing 102) and acorresponding ultrasonic detector detects the ultrasonic signals andrelays them to an appropriate component. Of course, the casing may alsobe a synthetic material having portions of suitable materials forcarrying an ultrasound signal. As discussed above with regard to theoptical signal configuration, each component can have both an ultrasonicgenerator and detector such that two-way communication betweencomponents is possible and mutiplexers and demultiplexers can beutilized such that certain components can operate at selectedfrequencies and/or wavelengths and not interfere with other componentson the bus.

In another embodiment, the casing 102 is a casing of a CPU of a computer200. In yet another implementation, the casing 102 is a casing of acellular telephone 300. As discussed above, such embodiments are givenby way of example only and not to limit the scope or spirit of thepresent invention.

Referring now to FIGS. 3 and 4, there is shown a computer CPU 200 andcellular telephone 300, respectively, in which similar number seriesdenote similar features to that of FIG. 1 (i.e., casing 102 correspondswith casings 202 and 302, etc.). Those skilled in the art willappreciate that the casings 202, 302 can be made smaller than aconventional counterpart device having the same number of internalcomponents or be able to house more components in the same size casing.Thus, the present invention can provide a miniaturization of electronicdevices, particularly portable electronic devices while eliminating theproblems associated with wiring, such as signal speed, poor connections,and failure over time due to brittleness and other insulation failures.The waveguide portion 108 also provides for a flexible design and layoutof the electronic components as well as the ability to easily add acomponent on the communication bus (waveguide portion 108) of thedevice. For example, where the waveguide portion 108 is deposited on asubstantial portion of the inner surface of the casing 102, theelectronic components can be distributed or added on any portion of thecasing where the waveguide portion 108 is deposited.

Examples of other devices not shown which can benefit from the methodsdisclosed herein are PDA's (personal digital assistants), cordlesstelephones, VCR's, portable CD and MP3 players, digital cameras, DVDplayers, and televisions. Such a listing is given by way of example onlyand is not intended to be exhaustive of any other electronic devices.Although discussed as electronic components, such components can alsohave a mechanical or chemical function as well as anelectronic/electrical function. These mechanical and/or chemicalfunctions can be housed in a portion of the interior of the casing thathas been freed up by having the electronic components distributed on thecasing.

Referring specifically to FIG. 3, there is shown a computer CPU 200having a casing 202 defining an interior 204. The casing has an outerportion 206 and a waveguide portion 208 that carries a signal 201.Transmitters 210 and detectors 214 are operatively connected to thewaveguide portion 208 and mounted to respective electronic components212, 216. Those skilled in the art will appreciate that the computer CPU200 can be made smaller, particularly, thinner in height (H) thanconventional CPU's that utilize conventional wiring between components.Alternatively, the computer CPU 200 can house more components than wouldbe possible for a similarly sized CPU of the prior art that utilizesconventional wiring between components. Furthermore, the CPU 200 has amore versatile design and can be upgraded with additional components atany place on the waveguide portion.

Referring specifically to FIG. 4, there is shown a cell phone 300 havinga casing 302 defining an interior 204. The casing also carries anantenna 305, a display 303, and a keyboard and other features (notshown). The casing 302 has an outer portion 306 and a waveguide portion308 that carries a signal 301. Transmitters 310 and detectors 314 areoperatively connected to the waveguide portion 308 and mounted torespective electronic components 312, 316. Those skilled in the art willappreciate that the cell phone 300 can be miniaturized as compared toconventional cell phones that utilize conventional wiring betweencomponents. Alternatively, the cell phone 300 can house more componentsthan would be possible for a similarly sized cell phones of the priorart that utilizes conventional wiring between components. Additionally,the cell phone 300 is better able to withstand shock, for example fromdropping the cell phone 300 on a hard surface. The increased shockresistance is due to the elimination of brittle wiring, includingprinted circuit boards and wiring harnesses and connecters.

Referring now to FIGS. 5 and 6, another embodiment of a device is shown,the device being in the form of a cellular telephone and referred togenerally by reference numeral 400. Typically, electrical/electroniccomponents of some devices, such as projectiles, are encased in apotting material, such as an epoxy, to harden the components againstnoise and shock due to the high acceleration and/or impact experiencedby the projectile. In the embodiment of FIGS. 5 and 6, the pottingmaterial 402, which can be a solid, such as an epoxy, a gel, or a liquidis disposed within a casing 401 of the cellular telephone and is used asa communication bus between electrical/electronic components 404. Thecommunication can be wholly within the potting material 402 or may bepartially within the potting material 402 and partially in free space.Although many devices can be subjected to such noise and/or shock, acellular telephone is described by way of example because of itstendency to be dropped or otherwise subjected to shock.

The communication through the potting material is carried out with atransmitter 406, which outputs any wavelength radiation that canpropagate through the potting material 402 and detected by a receiver408. It is preferred that the potting material 402 be a solid, such asan epoxy to provide hardening of the cellular telephone to shock andnoise and it is further preferred that the radiation used as acommunication medium is IR energy, preferably from a IR diode. In suchan example, the epoxy need not be transparent or substantiallytransparent as long as it can carry an IR signal over a requireddistance, such as several hundred mm or less. An example of such anepoxy is Dolphon® CC-1024-A Low Viscosity Potting and Casting EpoxyResin with RE-2000 Reactor mixed at a ratio of 10 parts resin to 1 partreactor, each of which is distributed by John C. Dolph Company. The sameepoxy resin and reactor can be used for the waveguide portions 108, 208,or 308 discussed above with regard to FIGS. 1, 3, and 4.

IR technology is well known in the art, particularly in the art ofremote control of electronic consumer goods. The IR data association(IrDA®) has standards for communicating data via short-range infraredtransmission. Transmission rates fall within three broad categories SIR,MIR and FIR, SIR (Serial Infrared) speeds cover transmission speedsnormally supported by an RS-232 port. MIR (Medium Infrared) usuallyrefers to speeds of 0.576 Mb/s to 1.152 Mb/s. FIR (Fast Infrared)denotes transmission speeds of about 4 Mb/s. The standard has beenmodified for faster transmission speeds up to 16 Mb/s (referred to asvery fast Infrared VFIR). Although not preferred, visible light, forexample from a laser diode, may also be used to transmit communicationsignals through the potting material 402.

The transmitters 406 may be carried on printed circuit boards 410 whichmay also be encased in the potting material 402 or disposed freelythroughout the potting material 402. The printed circuit boards each 410preferably carry their own power supply, such as a battery 412 toeliminate internal wiring. Each of the electronic/electrical components404 has a receiver 408 for communicating with the transmitters 406. Asdiscussed above with regard to the first embodiment, each of theelectrical/electronic components 404 preferably have a receiver 408 anda transmitter 406 such that they can carry out a two-way communication.An example of such a transceiver module 500 is shown in the schematicdiagram of FIG. 6. FIG. 6 shows an (IrDA®) transceiver manufactured bySharp Inc. (2P2W1001YP) which is relatively inexpensive and contains ahigh speed, high efficiency low power consumption light emitting diode(LD), a silicon PIN photodiode (PD) and a low power bipolar integratedcircuit. The circuit contains an LED driver (TRX) and a receiver circuit(RCX) that delivers 4 Mb/s operation for distances of 1 meter. The LEDemitter transmits at a nominal wavelength of 880nm with a radiantintensity in the range of 100 to 500 mW.sr⁻¹, with a radiation angle of+/−15 degrees. The pin photodiode has an integrated amplifier (AMP) andcomparator (CMP), which provide a fixed voltage output over a broadrange of input optical power levels and data rates. The same or similartransceiver module 500 can also be used for the other embodimentsdescribed above with regard to FIGS. 1, 3, and 4.

The Infrared Data Association (IrDA) was formed in 1993. The InfraredData Association specified wireless communication standard betweenportable devices, such as, computers, printers, digital cameras, etc.,and is preferably used in the present communication links. The standardis widely used by the industry. For the physical layer, IrDAtransreceivers broadcast infrared pulses in a cone that extends 15degrees half angle to 30 degrees half angle. The typical range for IrDAcommunications is from 5 cm to 60 cm away from a transreceiver in thecenter of the cone. In practice, there are some devices on the marketthat do not reach one meter, while other devices may reach up to severalmeters. The IrDA standard also specifies IrLAP (Link Acsess Protocol)and IrLMP (Link Management Protocol).

For the particular case of establishing communications links in enclosedvolumes such as within projectile body, due to the following reasons,the communication protocol scheme must tune the transmission rates sothat the effects of multi-path effects do not interfere with theoperation of the communications links.

It is noted that in the case of projectiles or other similar cases, thespace within which the present optical communication bus is beingestablished is enclosed, and in most cases with materials that are nottransparent to the light spectrum being used. In addition, severalelectronics boards or devices or the like, some of which may have beenpotted in potting materials, may be located at different locationswithin the projectile body and communications links may have to beestablished between them. In addition, other electrical or mechanicalcomponents or energetic materials or the like which are generallynon-transparent and may even have highly reflective surfaces are usuallypresent in guided and smart munitions. For these reasons, when thetransmitter element of an IR transreceivers transmits a pulse, thereceiver element located on a separate IR transreceivers at a differentlocation within the projectile body will receive the (“leading”) pulsesignal, but may also receive several other (“following”) pulses(pulse-like signals) due to the multi-path effects, depending on theirrelative locations within the projectile body. The “following” pulsesare generally weaker and die down quickly after several reflections dueto absorption and dispersion. However, up to certain signal strengththreshold, the “following” pulses may still register as transmittedsignal.

For this reason, once a pulse is transmitted and the aforementioned“leading” pulse signal is received (by all present receivers), the nextpulse can only be transmitted once the strength of the aforementioned“following” pulses have fallen below the aforementioned strengththreshold. The time that it takes for the strength of the “following”pulses to fall below the aforementioned threshold determines the maximumtransmission rate that can be used in the projectile. The said maximumtransmission rate can be readily determined experimentally bytransmitting a single pulse and waiting until no pulses above theaforementioned signal strength threshold is detected from any one of thepresent receivers. This process is preferably implemented on theprocessor being used to set up the communications bus insider theprojectile to allow an appropriate transmission rate to be automaticallyselected.

It is appreciated by those skilled in the art that even though IrDAtransreceivers are preferably used in the present munitions and the likeapplications for setting up a communications bus, however, if aparticular application demands, optical transreceivers that operate atdifferent light spectrum may also be employed.

The casing 402 can also be provided with a window portion 403, as shownin FIG. 5, which can be used to upload or input data or instructionsinto components of the cellular telephone through the potting material402 (or through the waveguide portions 108, 208, and 308 discussedabove). In a preferred implementation, the window portion 403 is inoptical communication with the waveguide portion 108, 208, 308 orpotting material 402 and transmits any input signals to the appropriatecomponents on the interior of the cellular telephone. Although describedin terms of a transparent window 403 and signal, the input signal can beany signal that propagates through the waveguide portion 108, 208, 308or potting material 402, such as an IR or ultrasound signal.Furthermore, the window 403 does not have to be a transparent window butmerely a portion of the casing, which is capable of transmitting asignal from the exterior of the cellular telephone to one or morecomponents on the interior of the cellular telephone.

Referring now to FIG. 7, there is shown a cellular telephone accordingto another embodiment of the present invention, in which similarreference numerals from FIG. 5 denote similar features, the cellulartelephone of FIG. 7 being referred to generally by reference numeral600. FIG. 7 is similar to that of FIG. 5 with the exception that thepotting material does not have to completely encase a portion of thecellular telephone's interior. The interior of the cellular telephoneincludes portions of free space 610 (which may be filled with air orother gases or may be evacuated. Although all of the components 404, 408are shown encased in the potting material 402, they can also be providedin the free space 610 or partially in the free space 610. Thus, thecommunication between components is not only through the pottingmaterial 402 but can also be done through the free space 610 inside thecellular telephone.

While there has been shown and described what is considered to bepreferred embodiments of the invention, it will, of course, beunderstood that various modifications and changes in form or detailcould readily be made without departing from the spirit of theinvention. It is therefore intended that the invention be not limited tothe exact forms described and illustrated, but should be constructed tocover all modifications that may fall within the scope of the appendedclaims.

1. A device other than a projectile, the device comprising: a casing, atleast a portion of which contains a potting material acting as theoptical waveguide material; a transmitter for transmitting a pulse basedsignal at least partially through the potting material; and a receiverfor receiving the pulse based signal after one or more reflections ofthe pulse based signal from interior surfaces of the casing; the pulsebased signal having a pulse rate configured such that a subsequent pulsedoesn't interfere with reflections from an immediately previous pulse.2. The device of claim 1, wherein the potting material is selected froma group consisting of a solid, a gel, and a liquid.
 3. The device ofclaim 2, wherein the potting material is the solid and the solid is anepoxy resin.
 4. The device of claim 1, wherein the signal is an infraredsignal.
 5. The device of claim 1, wherein the casing includes a windowthrough which an input signal is transmitted from an exterior of thecasing to at least one of the potting material and receiver.
 6. A methodfor transmitting signals between components in a device other than aprojectile, the method comprising: filling at least a portion of thedevice with a potting material acting as an optical waveguide material;transmitting a pulse based signal at least partially through the pottingmaterial acting as the optical waveguide material; reflecting the pulsebased signal from interior surfaces of the device; and receiving thepulse based signal after one or more reflections; wherein the pulsebased signal has a pulse rate configured such that a subsequent pulsedoesn't interfere with reflections from an immediately previous pulse.